This ability feels really nice for blood tanking (and for everyone who needs blood rune dump) Obviously it's not that good in 5mans as everything dies in seconds.

Still doable with some timing, and if its packs of trash the haste really helps aswell if you take out the first mob and then move on to the next one. 2H frost is pretty good at raping that single mob in the pack anyways, and the 50% haste gives some heavy rune regeneration.

@Kunay assuming you mean that its 5s instead of 10s? Thats an intended change, tooltips only get updated with client-side updates IIRC.